InputText: cleanup/rework old comments + remove unnecessary indent in callback and main block setting apply_new_text.

Amend 00f12b9a0, 3349296370 etc.

imgui_internal.h

@@ -1258,6 +1258,7 @@ struct IMGUI_API ImGuiInputTextState
     void        OnKeyPressed(int key);      // Cannot be inline because we call in code in stb_textedit.h implementation
     void        OnCharPressed(unsigned int c);
     float       GetPreferredOffsetX() const;
+    const char* GetText()                   { return TextA.Data ? TextA.Data : ""; }
 
     // Cursor & Selection
     void        CursorAnimReset();

imgui_widgets.cpp

@@ -5217,7 +5217,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         render_selection |= state->HasSelection() && (RENDER_SELECTION_WHEN_INACTIVE || render_cursor);
     }
 
-    // Process callbacks and apply result back to user's buffer.
+    // Process revert and user callbacks
     const char* apply_new_text = NULL;
     int apply_new_text_length = 0;
     if (g.ActiveId == id)
@@ -5247,18 +5247,6 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             }
         }
 
-        // FIXME-OPT: We always reapply the live buffer back to the input buffer before clearing ActiveId,
-        // even though strictly speaking it wasn't modified on this frame. Should mark dirty state from the stb_textedit callbacks.
-        // If we do that, need to ensure that as special case, 'validated == true' also writes back.
-        // This also allows the user to use InputText() without maintaining any user-side storage.
-        // (please note that if you use this property along ImGuiInputTextFlags_CallbackResize you can end up with your temporary string object
-        // unnecessarily allocating once a frame, either store your string data, either if you don't then don't use ImGuiInputTextFlags_CallbackResize).
-        const bool apply_edit_back_to_user_buffer = true;// !revert_edit || (validated && (flags & ImGuiInputTextFlags_EnterReturnsTrue) != 0);
-        if (apply_edit_back_to_user_buffer)
-        {
-            // Apply current edited text immediately.
-            // Note that as soon as the input box is active, the in-widget value gets priority over any underlying modification of the input buffer
-
         // User callback
         if ((flags & (ImGuiInputTextFlags_CallbackCompletion | ImGuiInputTextFlags_CallbackHistory | ImGuiInputTextFlags_CallbackEdit | ImGuiInputTextFlags_CallbackAlways)) != 0)
         {
@@ -5340,7 +5328,8 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             }
         }
 
-            // Will copy result string if modified
+        // Will copy result string if modified.
+        // FIXME-OPT: Could mark dirty state from the stb_textedit callbacks
         if (!is_readonly && strcmp(state->TextSrc, buf) != 0)
         {
             apply_new_text = state->TextSrc;
@@ -5348,9 +5337,9 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             value_changed = true;
         }
     }
-    }
 
     // Handle reapplying final data on deactivation (see InputTextDeactivateHook() for details)
+    // This is used when e.g. losing focus or tabbing out into another InputText() which may already be using the temp buffer.
     if (g.InputTextDeactivatedState.ID == id)
     {
         if (g.ActiveId != id && IsItemDeactivatedAfterEdit() && !is_readonly && strcmp(g.InputTextDeactivatedState.TextA.Data, buf) != 0)
@@ -5363,12 +5352,14 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         g.InputTextDeactivatedState.ID = 0;
     }
 
-    // Copy result to user buffer. This can currently only happen when (g.ActiveId == id)
+    // Write back result to user buffer. This can currently only happen when (g.ActiveId == id) or when just deactivated.
+    // - As soon as the InputText() is active, our stored in-widget value gets priority over any underlying modification of the user buffer.
+    // - Make sure we always reapply the live buffer back to the input/user buffer before clearing ActiveId, even thought strictly speaking
+    //   it was not modified on this frame. This allows the user to use InputText() without maintaining any user-side storage.
+    //   (PS: if you use this property together with ImGuiInputTextFlags_CallbackResize, you are at the risk of recreating a temporary
+    //    allocated/string object every frame. Which in the grand scheme of scheme is nothing, but isn't dear imgui vibe).
     if (apply_new_text != NULL)
     {
-        //// We cannot test for 'backup_current_text_length != apply_new_text_length' here because we have no guarantee that the size
-        //// of our owned buffer matches the size of the string object held by the user, and by design we allow InputText() to be used
-        //// without any storage on user's side.
         IM_ASSERT(apply_new_text_length >= 0);
         if (is_resizable)
         {